YT Resume

A Firefox and Chromium extension that privately saves and restores playback positions for standard YouTube videos. Progress remains in the current browser profile—there is no account, server, analytics, or remote code.

Behavior

• Restores one local checkpoint per YouTube video.
• Shows an in-player resume message by default, with a setting to hide it.
• Saves every five seconds and on pause, seek, navigation, and page exit.
• For timestamp links, restores the local checkpoint unless the URL time is more than one minute ahead.
• Ignores positions below five seconds and clears completed or nearly completed videos.
• Supports 7, 30, 90, 180, 365-day, or unlimited retention; the default is 7 days.
• Supports regular youtube.com/watch videos, including playlist links.
• Skips YouTube Mix and Radio playback (start_radio=1) so tracks from those sessions do not resume partway through.
• Does not run in Private Browsing or Incognito and currently excludes Shorts, live streams, premieres, embeds, and YouTube Music.

Resource use

The content script is event-driven while idle: it has no permanent polling interval and no periodic save timer on paused videos or non-watch YouTube pages. During playback, one five-second timer preserves the agreed crash-recovery accuracy. Repeated writes are skipped when buffering prevents the playhead from advancing, and stale duplicate tabs stop saving until the user interacts with them again.

The extension has no runtime dependencies, network requests, analytics, or background work outside YouTube.

Develop

Requires Firefox 140+ or Chromium 99+, plus Node.js.

npm ci
npm test
npm run lint
npm run start:firefox
npm run start:chromium

npm start is an alias for npm run start:firefox. Shared runtime files live in src/shared/; browser-specific manifests and entry points live in src/firefox/ and src/chromium/. Development, test, lint, and build commands assemble loadable extensions under dist/. The start commands keep those generated files synchronized while they run.

To refresh both generated extensions without starting a browser:

npm run prepare:dist

To load the extension manually after running npm ci or npm run prepare:dist:

• Firefox: open about:debugging, choose This Firefox, select Load Temporary Add-on, and choose dist/firefox/manifest.json.
• Chromium: open chrome://extensions, enable Developer mode, select Load unpacked, and choose the dist/chromium/ directory.

Build

npm run build

Browser-specific ZIPs are written to web-ext-artifacts/firefox/ and web-ext-artifacts/chromium/.

Stored data

Each record contains only a YouTube video ID, playback position, duration, and local timestamps used for conflict resolution and expiry. Video titles are shown transiently in the popup but are not stored.

License

YT Resume is free and open-source software licensed under the GNU General Public License v3.0.